Mbh 3.308.4a

Vaisampayana continued, “Hearing these words of Indra, Karna was filled with delight and seeing that his purpose was about to be accomplished he approached Vasava, and intent upon obtaining a dart incapable of being baffled, he addressed Indra, saying, ‘Do thou, O Vasava, in exchange for my coat of mail and ear-rings, give me a dart incapable of being baffled, and competent to destroy hosts of enemies when arrayed in order of battle!’ Thereupon, O ruler of earth, fixing his mind for a moment on the dart (for bringing it there), Vasava thus spake unto Karna, ‘Do thou give me thy ear-rings, and the coat of mail born with thy body, and in return take this dart on these terms! When I encounter the Daitya in battle, this dart that is incapable of being baffled, hurled by my hand, destroyeth enemies by hundreds, and cometh back to my hand after achieving its purpose. In thy hand, however, this dart, O son of Suta, will slay only one powerful enemy of thine. And having achieved that feat, it will, roaring and blazing, return to me!’ Thereat Karna said, ‘I desire to slay in fierce fight even one enemy of mine, who roareth fiercely and is hot as fire, and of whom I am in fear!’ At this, Indra said, ‘Thou shall slay such a roaring and powerful foe in battle. But that one whom thou seekest to slay, is protected by an illustrious personage. Even He whom persons versed in the Vedas call ‘the invincible Boar,’ and ‘the incomprehensible Narayana,’ even that Krishna himself, is protecting him!’ Thereupon Karna replied, ‘Even if this be so, do thou, O illustrious one give me the weapon that will destroy only one powerful foe! I shall, on my part, bestow on thee my mail and ear-rings, cutting them off my person. Do thou, however, grant that my body, thus wounded, may not be unsightly!’ Hearing this, Indra said, ‘As thou, O Karna, art bent upon observing the truth, thy person shall not be unsightly, or shall any scar remain on it.